A consecutive joint shear strength model considering the 3D roughness of real contact joint surface

作     者：Liren Ban Zhigang Tao Weisheng Du Yuhang Hou Liren Ban;Zhigang Tao;Weisheng Du;Yuhang Hou

作者机构：School of Civil and Transportation EngineeringBeijing University of Civil Engineering and ArchitectureBeijing 100044China State Key Laboratory of Deep Geotechnical Mechanics and Deep Underground EngineeringBeijing 100083China State Key Laboratory of Geomechanics and Geotechnical EngineeringInstitute of Rock and Soil MechanicsChinese Academy of SciencesWuhan 430071China School of Mechanics and Civil EngineeringChina University of Mining and TechnologyBeijing 100083China Deep Mining and Rock Burst Research BranchChina Coal Research InstituteBeijing 100013China State Key Laboratory of Hydroscience and EngineeringTsinghua UniversityBeijing 100084China 

出 版 物：《International Journal of Mining Science and Technology》 (矿业科学技术学报（英文版）)

年 卷 期：2023年第33卷第5期

页      面：617-624页

核心收录：

学科分类：081901[工学-采矿工程] 0819[工学-矿业工程] 08[工学] 

基　　金：National Natural Science Foundation of China(Nos.52208328 and 52104090) Innovation Fund Research Project of State Key Laboratory for GeoMechanics and Deep Underground Engineering(No.SKLGDUEK202201) Open Research Fund of State Key Laboratory of Geomechanics and Geotechnical Engineering(No.Z020007). 

主　　题：Shear strength Actual contact area 3D roughness Shear test 

摘      要：A consecutive joint shear strength model for soft rock joints is proposed in this paper,which takes into account the degradation law of the actual contact three-dimensional(3D)roughness.The essence of the degradation of the maximum possible dilation angle is the degradation of the 3D average equivalent dip angle of the actual contact joint asperities.Firstly,models for calculating the maximum possible dilation angle at the initial and residual shear stress stages are proposed by analyzing the 3D joint morphology characteristics of the corresponding shear stages.Secondly,the variation law of the maximum possible dilation angle is quantified by studying the degradation law of the joint micro convex body.Based on the variation law of the maximum possible dilation angle,the maximum possible shear strength model is proposed.Furthermore,a method to calculate the shear stiffness degradation in the plastic stage is proposed.According to the maximum possible shear strength of rock joints,the shear stress-shear displacement prediction model of rock joints is obtained.The new model reveals that there is a close relationship between joint shear strength and actual contact joint roughness,and the degradation of shear strength after the peak is due to the degradation of actual contact joint roughness.